The electromagnetic spectrum has frequencies associated with it in which electromagnetic radiation may be radiated. The electromagnetic spectrum can be divided into frequency regions that exhibit common properties useful in science and technology. For example, the audible range of frequencies is approximately between 20 Hertz (Hz) to 20,000 Hz which humans can here. There is a radio frequency band of the electromagnetic spectrum which is allocated for radio, including cellular phones, and television communication systems. Electromagnetic radiation in the radio frequency bands tends to bend around, reflect off of and pass through objects, and thus, is favorable to communication systems. There is a narrow band referred to as the visible spectrum between 3.95×1014 Hz to 7.90×1014 Hz over which the radiant energy is visible to a human eye. The visible spectrum may divided into frequencies of color. Just below the visible spectrum is the infrared (IR) frequency spectrum which is in the range between 3×1011 Hz to 4×1014 Hz which is not visible to the human eye. More typically, the frequency of electromagnetic radiation in the IR frequency spectrum is expressed in wavelengths because of its light properties. In this case, the wavelength of light (λ) is proportional to the inverse of the frequency (f) and can be expressed in equation form as λ=C/f where C is the speed of light.
Infrared (IR) radiation having properties of light travels in a straight, or line-of-sight, path. IR radiation is blocked by opaque objects and typically reflects well off of only hard, mirror-like surfaces. Thus, electromagnetic radiation in the IR frequency spectrum, referred to as IR radiation, is not typically used in audible communication systems such as cellular telephones and voice radios.
One system that uses infrared radiation for data communication is an electronic game for children which is more commonly referred to as a laser tag or LAZER TAG® game. One embodiment of a laser tag game is disclosed in U.S. Pat. No. 5,904,621 titled “ELECTRONIC GAME WITH INFRARED EMITTER AND SENSOR” by David Bernard Small et al. In the embodiment of the laser tag game described in U.S. Pat. No. 5,904,621, only data is communicated via the infrared emitter and sensor between each of the hand-held electronic toy guns. The data typically communicated is a tag that is fired between the hand-held electronic toy guns. In order for data to be communicated, the data is modulated or encoded onto a carrier frequency. The carrier waveform modulated by the data is then transmitted using an infrared beam. There is no voice communication capability provided by the hand-held electronic toy guns in U.S. Pat. No. 5,904,621.
Like reference numbers and designations in the drawings indicate like elements providing similar functionality.